Dependence of the charging effects on the tunnel oxide thickness in Si nanoparticles embedded in a SiO2 layer

Dependence of the charging effects on the tunneling oxide thickness in Si nanoparticles embedded in a SiO₂ layer was investigated by using electrostatic force microscopy (EFM) measurements. EFM images showed that the stored charge in the Si nanoparticles increased with an increase in the applied bias voltage of the EFM tip. The variation of tunnel oxide thickness affected the tunneling threshold voltages, at which the carriers begun to tunnel from the Si substrate to the Si nanoparticles. These results indicate that the observed charging effects of Si nanoparticles embedded in a SiO₂ layer provide important informations on potential applications in nonvolatile memories with floating gates consisting of Si nanocrystals embedded in a SiO₂ layer.